"He was great. For a freshman in this environment, against those guards, to have this game. He was superb."

Irving was every one of those and a Scrabble-board worth more in top-ranked Duke's 84-79 win over No. 5 Michigan State. He scored 31, handed out four assists, pulled down six rebounds and had a pair of both steals and blocks.

The 31 points were three removed from the all-time Duke record, held by J.J. Redick. Redick, however set his mark against a Virginia team that would go 16-16 in 2003 and lose in the second round of the NIT. Irving had his against a Final Four team with the 2009 Big Ten player of the year in the backcourt and a penchant for playing defense with less regard for personal space than an airport screener.

Perhaps Krzyzewski had just run out of words for Irving, the peach-fuzzed 18-year-old who has almost certainly played hero for Duke more often than he has to shave. It was the second time in eight days he had led the Blue Devils against a physical top-six-ranked team, scoring a then career-best 17 to lead Duke over Kansas State last Tuesday.

So, Coach, may we suggest tough?

The signature matchup and final game of the ACC-Big Ten Challenge was billed as a heavyweight bout. It was. If you mean MMA

Michigan State, the team known for practicing in shoulder pads, brought the Blue Devils so physical a contest that even the school's mascot likely ended up more black-and-blue than usual.

"It was a man's game," Krzyzewski said of the contest. "Both teams played it."

Irving appeared to twist his ankle early in the first half – after running back full speed to block a shot on a Michigan State fastbreak – and limped off. He returned less than three minutes later. Center Mason Plumlee had to be helped off late in the second half after also injuring an ankle. He too, returned. Nolan Smith took an intentional foul from Derrick Nix and walked to the free thrown line. And in between bodies in white and green crashed and banged like billiard balls.

Yet at the center of the "man's game" was the youngest Blue Devil on the court.

With seniors Kyle Singler and Nolan Smith struggling and Duke up 13-7, he scored 11 of the team's 15 points midway through the first half to keep Michigan State at arm's length. He scored 18 in the first half as Smith fought foul trouble. He added 13 in the second and dribbled the game away in the final minutes, even with Spartan senior Kalin Lucas desperately trying to swat a ball loose.

"Kyrie played like a veteran," said Smith, whose locker is next to Irving's and has played the role of bigger brother to Duke's prized freshman. "He was very mature tonight, and for a freshman to show up on this stage is huge. He doesn't play like a freshman, and he hasn't acted like a freshman."

Perhaps it's because Krzyzewski hasn't coached him like one. The Hall of Fame coach remodeled his offense in the offseason, swapping out a brutally efficient, if not necessarily photogenic, halfcourt offense for an uptempo fastbreak offense dictated by its freshman point guard.

"I haven't coached him like a freshman, I've coached him like a really good player," Krzyzewski said. "You have to let a really good player make some mistakes and learn. And he's done that. But you also have to let him follow his instincts."

Irving hasn't just taken to it. He may be the team's best player. His assist-to-turnover ratio is 2.29 and he's averaging 16.9 points per game, a scoring rate that would put him behind only Mike Gminski and Gene Banks on Duke's all-time freshman list.

Wednesday night, he proved there was plenty of smash to do with dash, leading his team to a win in the exact sort of game it might've been pushed around in between 2005 and 2009.

Irving has a way of finding a path through traffic like he's dribbling along to an old Arthur Murray dance step sheet, but against Michigan State, no points came freely. Few of his shots were uncontested, few passes through wide-open lanes. He went to the free throw line for 16 shots. He hit 13.

He helped pick up a team that needed a difference-maker on a night its two All-American candidate teammates couldn't.

Not bad for a player who spend Monday sick to his stomach.

"He took care of business, and when things got tough, he made big plays for us," Singler said. "He had a great performance."

He led. Duke followed.

Tough, like its point guard. Tough, like its 2010 championship team.

Michigan State would never quite go away. Korie Lucious matched Irving style point for style point and Kalin Lucas proved dangerous even if still not up to full speed. The Spartans, despite committing 20 turnovers, didn't wilt in a college gym, that at a frenzy like Wednesday night, is a little like trying to play inside a blender set to puree.

"If I learned something about my team tonight, at least we're starting to battle back a little bit," Michigan State coach Tom Izzo said. "We had our chances to fold, but we kept coming back. We showed some grit."

So too did Duke, rolling with every heavy Spartan blow in a game that felt like a December prequel to a Final Four showdown.

Singler, who had struggled shooting all game long, hit two key 3-pointers in a 12-2 second-half run that gave Duke what little bit of breathing room it could muster, turning a 49-47 edge into a 61-49 edge. He was 2-11 from the floor before connecting on the pair.

When Michigan State made its last push, cutting the lead to 69-64 with 3:37 to play, Singler again played the role of tough guy, after an Irving layup was blocked. The senior dashed from the left wing and popped the ball back in with less than a second left on the shot clock, undefended, because the teeth of the defense had followed Irving.

When Mason Plumlee left the game with an injured ankle, Izzo selected Smith to shoot the free throws in his place. He had a missed three of his last free throws prior. He sank both.

And then there was Plumlee, Duke's lone's reliable paint presence, who scored 10 points, pulled down 10 rebounds and had five steals against Michigan State's rotation of big men.

"If we don't have him playing tonight the way he did, there's no way we're going to win."

Duke did, though, as it usually does in the ACC-Big Ten Challenge. The victory was Duke's 11th in a dozen tries in the series. Yet there were there were few questions about the made-for-TV event, which went to the Big Ten for a second straight year earlier in the night.

Perhaps because it was clear that while the Big Ten had won the battle, Kyrie Irving and Duke had won a war.